PROJECT SUMMARY Given the growing complexity of healthcare, continued problems related to quality and cost, and a widely- recognized 17-year evidence to practice gap, there is an urgent need for a rehabilitation resource center that supports the conduct of learning health systems (LHS) rehabilitation research and develops LHS researchers to advance the field of rehabilitation care. Brown University, the University of Pittsburgh (Pitt) and Boston University (BU), together with health system/health organization partners, are combining expertise and resources to create LeaRRN: the Learning Health Systems Rehabilitation Research Network. LeaRRN?s mission is to improve the quality, outcomes and value of rehabilitation care by fostering stakeholder-partnered research within and across LHSs. LeaRRN will build upon a well-established infrastructure and collaborative relationships at Brown, Pitt, and BU; faculty expertise in health services research, implementation science, stakeholder engagement, and informatics; and established and emerging partnerships with a diverse group of LHSs. LeaRRN?s overarching objective is to establish a national resource network to advance stakeholder- partnered, rehabilitation LHS research to improve quality of care, demonstrate value, and enhance patient and system outcomes. LeaRRN will include training to promote seven core LHS research competencies, including (1) using a system science approach, (2) asking meaningful questions, (3) applying appropriate research methods, (4) capitalizing on informatics, (5) championing research ethics, (6) optimizing quality improvement and implementation science, and (7) engagement, leadership and research management. LeaRNN will also support research innovation by convening health system stakeholders to identify priority topics to address through mentored collaborations (i.e., LHS Scholar opportunities and pilot studies). Finally, through techniques development, we will assess the needs of the rehabilitation research community, prioritize and design our resources and activities to respond to those needs, and evaluate our impact. LeaRRN?s specific aims are to: 1) create a LHS Innovation Hub that partners researchers with healthcare systems and engages stakeholders, including patients, providers, administrators, payers, and policymakers, to develop rehabilitation-focused LHS research questions; 2) provide funding and methodological/technical support for LHS Scholars and Pilot Study Awardees to transform research ideas into full-scale studies conducted in real-world practice; and 3) develop a knowledge repository, tailor LHS resources for rehabilitation and disseminate materials to advance best practices in rehabilitation LHS research. LeaRRN will serve as a resource and incubator for rehabilitation researchers interested in LHS research. The knowledge repository, investigative experience, collaborations, and evidence generated by LeaRRN will transform the delivery, quality, and outcomes of rehabilitation care.